During the planned maintenance of large-scale ethylene plants, due to the wide range of facilities and complicated process conditions, the remaining ethylene, propylene, and other materials in the system will inevitably be discharged into the torch combustion, causing both economic losses and environmental pollution. For this purpose, the Sinopec Qilu Petrochemicals olefins plant combines the technological features of the ethylene plant to develop the material recovery technology. In 1997, the company invested more than 60,000 yuan to configure the material recovery process pipeline, formulated a new plant shutdown operation program, and initially recycled ethylene and propylene mixtures. More than 100 tons of material. In view of the different temperatures of ethylene and propylene materials, after the two are mixed, some of the low-temperature ethylene is vaporized and discharged into the torch. They then undergo technological transformation, recovering ethylene and propylene separately, and successfully recovering ethylene and propylene. 260t. Since then, it has invested 100,000 yuan to further improve its technology and recovered 300 tons of ethylene and propylene materials during the shutdown of ethylene plants. In June of this year, the well-established material recovery technology recovered nearly 400 tons of ethylene and propylene materials for the Qilu ethylene plant, worth more than RMB 1 million.